It is known in the prior art to provide a multi-ply business form having one or more localized autogenous coatings each comprising both microscopic pressure-rupturable capsules containing a chromogenic material, and an electron acceptor material. One such form is disclosed in U.S. Pat. No. 4,425,386 to Chang. Each localized autogenous coating is capable of reacting under the impact of a printing stylus to release the chromagen from the capsules for reaction with the electron acceptor material to provide a visible image comprising address or other information. The use of such coatings advantageously enables the user of the form to selectively print one type of information on a coating located, for example, on an outside ply and a second type of information on a coating located on an inside ply.
It is also known in the prior art to selectively print information On a multi-ply business form using a chemically-reactive ribbon in which the ribbon for the printer is coated with a color-forming chromogenic material in solution. The mailer, rather than including a complete autogenous coating as in the Chang patent, simply includes a spot coating of color developer material located on the front of the mailer. This form is described in U.S. Pat. No. 4,172,605 to Welsch et al.
While the above-described mailers have certain advantages over conventional mailers that typically employ spot coatings of carbon ink on the backside of a detachable top record sheet, accurate placement of autogenous coatings on a mailer requires a complex and therefore expensive and unreliable manufacturing process. Moreover, it is often difficult to apply the localized autogenous coating in a uniform manner or without actually activating the capsules during application. The resulting coating is thus "bruised" or discolored and at least partly incapable of reacting with the printing stylus; the address or other information, therefore, may be inaccurate. The use of a chemically-reactive ribbon coated with chromogenic material in solution is likewise disadvantageous because the ribbon is expensive and has a short useful life.
It would therefore be advantageous to provide a multi-ply business form and method of manufacture therefor which overcomes these and other problems associated with the prior art.